Famous US radio talk show host Rush Limbaugh has admitted making racist comments while saying Luther star Idris Elba cannot play James Bond because he is black.

He made the comments on his show after a leaked email from Amy Pascal, the co-chairman of Sony Pictures Entertainment, suggested the British actor could fill the role of 007.

Limbaugh said: "James Bond is a total concept put together by Ian Fleming. He was white and Scottish. Period. That is who James Bond is, was.

"But now Sony is suggesting that the next James Bond should be Idris Elba, a black Briton, rather than a white from Scotland. But that's not who James Bond is and I know it's racist to probably even point this out."

The email also mentioned the forthcoming Bond film, Spectre, and that Daniel Craig's contract as 007 runs out in November 2015.

"We had 50 years of white Bonds because Bond is white", Limbaugh said. "Bond was never black. Ian Fleming never created a black Brit to play James Bond. The character was always white. He was always Scottish. He always drank vodka shaken not stirred and all that."

He then mocks the idea of selecting white actors to play black people, such as Scarlett Johansson to play Condoleezza Rice, or NFL athlete Michael Sam to be played by Hugh Grant.

"If Idris Elba is going to play James Bond and if that's a natural hit and that's the only way we can go and then let's see, how about Hugh Grant as Michael Sam?" Limbaugh said.

"Sometimes a story is just a story, but we can always make it better. We can always be more fair. We can always be more equal about it. So, fine and dandy. George Clooney and Kate Hudson as Barack and Michelle Obama, and you can have Idris Elba as James Bond."

Allegedly a Sony executive responded to Pascal and said: "We can't have black stars in a lead in the James Bond because foreign markets would not exhibit the movie."

It is not the first time Limbaugh has made outlandish statements. Last year he was condemned for using rape as an analogy when arguing against changes in the U.S. Senate concerning the filibuster rule.

Limbaugh's comments have received a mixed reaction on Twitter.